can one year gap after 12 create problem in finding jobs in future ?
No dear, there are vast number of students who pursue their higher studies after one or two years gap after 10+2. This happens may be because of the preparations taken for any certain exam or due to the dilemma of choosing the correct stream after 10+2. So even if you take one year gap, during your job interview this is not going to hamper your career at all, maximum they can ask for the reason and you have to answer tactically.
All the best!!